The Caterpillar D8 is a large track-type

Tracked vehicle

A tracked vehicle is a vehicle that runs on continuous tracks instead of wheels...

 tractor

Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

 designed and manufactured by Caterpillar

Caterpillar Inc.

Caterpillar Inc. , also known as "CAT", designs, manufactures, markets and sells machinery and engines and sells financial products and insurance to customers via a worldwide dealer network. Caterpillar is the world's largest manufacturer of construction and mining equipment, diesel and natural gas...

.
Though it comes in many configurations it is usually sold as a bulldozer

Bulldozer

A bulldozer is a crawler equipped with a substantial metal plate used to push large quantities of soil, sand, rubble, etc., during construction work and typically equipped at the rear with a claw-like device to loosen densely-compacted materials.Bulldozers can be found on a wide range of sites,...

 equipped with a detachable large blade and a rear ripper attachment.

History

• 1935: RD8 introduced.
• 1937: The "R" prefix dropped, D8 debuts.
• 1940s: 2U Series D8 introduced; engine power of 132 hp improved to 148hp.
• 1950: D8 new front-rounded grill that would last until D8K was replaced by D8L in 1982.
• 1955: 1H Series D8 ends production; 191 hp D8E and D8D introduced with new 1,246 cubic inch displacement (CID) D342 diesel engine. D8D had a torque converter and D8E had a direct drive transmission.
• 1956: D8D replaced by D8G.
• 1956: D8E replaced by D8F.
• 1958: 235 hp D8H introduced.
• 1965: Power increased to 270 hp
• 1974: 300 hp D8K replaced D8H.
• 1982: 335 hp D8L replaced D8K. The D8L was the first D8 with the elevated drive sprocket undercarriage.
• 1984: D8L SA (special application) for farming applications premiers. Available with a Three point hitch, for mounted implements.
• 1987: D8N at 285hp which was unveiled at CONEXPO '87 in Las Vegas
  Las Vegas metropolitan area
  The Las Vegas Valley is the heart of the Las Vegas-Paradise, NV MSA also known as the Las Vegas–Paradise–Henderson MSA which includes all of Clark County, Nevada, and is a metropolitan area in the southern part of the U.S. state of Nevada. The Valley is defined by the Las Vegas Valley landform, a ...
  
  . It also had a differential steer transmission — the first track-type Caterpillar tractor to have one.
• 1996: 305 hp D8R replaced D8N.
• 2000: D8R Series 2 replaced the D8R.
• 2004: 310 hp D8T ACERT replaced D8R Series 2.

Blades

Several types of bulldozer blade can be used on the front of the tractor:

• straight blade ("Syedy bhokachya-Blade"): A short blade with no lateral curve and no side wings. It can be used for fine grading
• angle blade: held by an U shape frame that has three holes on each side, to set the blade to 3 positions: right, center, and left.
• universal blade ("U-Blade"): A tall and very curved blade with large side wings to carry more material
• "S-U" combination blade: A shorter blade with less curvature and smaller side wings

People use various other blade types, including landfill U-Blades, woodchip U-blades, and two-way blades for work inside the holds of ships.

In the Media

The RD8 appeared as the 'Earthworm RD8' in the Joe E. Brown

Joe E. Brown (comedian)

Joseph Evans Brown was an American actor and comedian, remembered for his amiable screen persona, comic timing, and enormous smile. In 1902 at the age of nine, he joined a troupe of circus tumblers known as the Five Marvelous Ashtons which toured the country on both the circus and vaudeville...

movie 'Earthworm Tractors' (1936) with background shots of the Caterpillar factory.

External links

• Caterpillar D-Series Track-Type Tractors - Official Caterpillar website

• Caterpillar D8R Series II Track Type Tractor, (Bit-Ends, Edge-Cuttings, Protector and Tip Ripper